#include <iostream>
using namespace std;
char findletter(char *s)
{
	int countletter[256]={0}; 
	char *s1=s;
	while(*s1!='\0')
	{
		countletter[*(s1++)]++;
	}
	char result;
	s1=s;
	while(*s1!='\0')
	{
		if (countletter[*s1]==1)
		{
			
			break;
		}
		s1++;
	}
	//result=*s1;
	/*return 0;*/
	return *s1;
}

int main()
{

	char s[]="acdbadsfrvb";
    char a=findletter(s);
	cout<<a<<endl;
}